NOVA: Ape Genius

Above: Brian Hare playing with a juvenile chimpanzee in Lola Ya Bonobo, Democratic Republic of Congo.

At a research site in Fongoli, Senegal, a female chimpanzee breaks off a branch, chews the end to make it sharp, and then uses this rudimentary spear to skewer a tasty bush baby hiding inside a hollow tree.

It’s an astonishing breakthrough for primate researchers—the first time anyone has documented a chimpanzee wielding a carefully prepared, preplanned weapon. But it's only the latest in a slew of extraordinary new findings about ape behavior.